Bump xunit from 2.7.1 to 2.8.0 (#189)

Bumps [xunit](https://github.com/xunit/xunit) from 2.7.1 to 2.8.0.
- [Commits](xunit/xunit@2.7.1...2.8.0)

---
updated-dependencies:
- dependency-name: xunit
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

NLog.Windows.Forms.Tests/NLog.Windows.Forms.Tests.csproj

@@ -21,8 +21,8 @@
 		<AssemblyOriginatorKeyFile>NLog.snk</AssemblyOriginatorKeyFile>
 	</PropertyGroup>
 	<ItemGroup>
-		<PackageReference Include="xunit" Version="2.7.1" />
-		<PackageReference Include="xunit.extensibility.execution" Version="2.7.1" />
+		<PackageReference Include="xunit" Version="2.8.0" />
+		<PackageReference Include="xunit.extensibility.execution" Version="2.8.0" />
 		<PackageReference Include="xunit.runner.visualstudio" Version="2.4.3">
 			<PrivateAssets>all</PrivateAssets>
 			<IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>